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    Subject[PATCH 5.10 069/148] objtool: Default ignore INT3 for unreachable
    Date
    From: Peter Zijlstra <peterz@infradead.org>

    commit 1ffbe4e935f9b7308615c75be990aec07464d1e7 upstream.

    Ignore all INT3 instructions for unreachable code warnings, similar to NOP.
    This allows using INT3 for various paddings instead of NOPs.

    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
    Link: https://lore.kernel.org/r/20220308154317.343312938@infradead.org
    Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
    Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    tools/objtool/check.c | 12 +++++-------
    1 file changed, 5 insertions(+), 7 deletions(-)

    --- a/tools/objtool/check.c
    +++ b/tools/objtool/check.c
    @@ -2775,9 +2775,8 @@ static int validate_branch(struct objtoo
    switch (insn->type) {

    case INSN_RETURN:
    - if (next_insn && next_insn->type == INSN_TRAP) {
    - next_insn->ignore = true;
    - } else if (sls && !insn->retpoline_safe) {
    + if (sls && !insn->retpoline_safe &&
    + next_insn && next_insn->type != INSN_TRAP) {
    WARN_FUNC("missing int3 after ret",
    insn->sec, insn->offset);
    }
    @@ -2824,9 +2823,8 @@ static int validate_branch(struct objtoo
    break;

    case INSN_JUMP_DYNAMIC:
    - if (next_insn && next_insn->type == INSN_TRAP) {
    - next_insn->ignore = true;
    - } else if (sls && !insn->retpoline_safe) {
    + if (sls && !insn->retpoline_safe &&
    + next_insn && next_insn->type != INSN_TRAP) {
    WARN_FUNC("missing int3 after indirect jump",
    insn->sec, insn->offset);
    }
    @@ -2997,7 +2995,7 @@ static bool ignore_unreachable_insn(stru
    int i;
    struct instruction *prev_insn;

    - if (insn->ignore || insn->type == INSN_NOP)
    + if (insn->ignore || insn->type == INSN_NOP || insn->type == INSN_TRAP)
    return true;

    /*

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